Carburetor



Jan, 20, 1925.

C. W. G. LITTLE CARBURE'IOR Filed Dec. 27, 1919 2 sheets -sheet 1 J)Pea/6f PM 456% I Jan. 20, 192 1,523,815

' C. W. G. LITTLE CARBURETOR Filed Dec. 27, 1919 2 Sheets-Sheet 2 III gA Patented Jan. 2t), 1925..

CHARLES WILLIAM GODSON LITTLE, OF ENFIELD, ENGLAND.

CARBURETOR.

Application filed December 27, 1919. Serial No. 347,813.

To all whom it may concern:

Be it known that 1, CHARLES VILLIAM Gonsox LITTLE, a subject of the Kingof Great Britain and Ireland, and resident of Enlield, England, haveinvented new and useful Improvements in Carburetors, of which thefollowing is a specification.

This invention relates to certain improvements in carburetors, and thenature and objects of the invention will be readily understood by thoseskilled in the art in the light of the following detailed descriptionand explanation of the accompanying drawings illustrating what I atpresent believe to be the preferred embodiments or mechanicalexpressions of my invention from among other forms, arrangements,combinations, and constructions within the spirit and scope thereof.

The present invention relates particularly to carburetors for internalcombustion rotors and includes as one of its objects the provision ofsuch a carburetor in which the proportions of air and fuel forming thecombustible mixture supplied to the motor are varied by the operation ofthe throttle member which controls the supply of combustible mixturefrom the carburetor to the motor so that a proper combustible mixture isformed for each position of the throttle throughout the working range ofthe -motor.

A further object of the invention is to provide a carburetor in whichmeans for admitting ir to the fuel before discharge into the mixingchamber of the carburetor to form a primary mixture, is controlled bythe throttle to vary the proportions of air and. fuel forming theprimary mixture discharged into the mixing chamber in relation to theposition of the throttle, and which means is adjustable independently ofthe throttle to permit variation of the propor- -tions of fuel and airforming the said primary mixture throughout the working range of thethrottle.

A further object of the invention is to provide a carburetor in whichthe proportions of air and fuel forming the combusti ble mixture arevaried by the operation of the throttle, with auxiliary andindependently operable means for varying the combustible mixtureproportions for heavy load operating conditions without disturbing oraiiecting the normal adjustment of the carburetor for light loadoperating conditions.

A further object of the invention is to provide a carburetor withindependent ad justable air admission means for admitting air directlyto the carburetor mixing chamber to vary the combustible mixture whenthe main air admission port of the carburetor is restricted by theposition of the throttle to operate a motor for light load conditions.

A still further object of the invention is to provide certainimprovements in the construction of the fuel and air intake passages ofa carburetor and in the construction and mounting of the dischargenozzle or orifice whereby a proper and complete atomization of theliquid fuel is obtained.

A still further object of the invention is to provide certainimprovements in the con struction and mounting of the carburetor bodyand the float chamber and in the manner of operatively connecting andarranging these elements thereof.

Various other objects and advantages will appear and be readilyrecognized and appreciated by those familiar with this art from thefollowing detailed description and explanation of the accompanyingdrawings.

Fig. 1 is a vertical section, certain parts being shown in elevation.

Fig. 2 is a top plan, the float chamber of the carburetor being omitted.

Fig. 3 is a side elevation.

Figs. at and 5 are sectional views of certain details of construction.

Fig. 6 is a detail sectional view taken on the line 0002 ofFig. 1.

The carburetor comprise-s the body 1 provided with the main air inlet 2at the lower part thereof extending through one side of the body 1 andin open communication with the atmosphere. The main air inlet 2 at itsupper end is in direct communication with and discharges into the mixingchamber of the carburetor, so that an air supply passage is formed fromatmosphere through one side of the body 1 and passing into and upwardlythrough the body, to and dis charging into the arburetor mixing chamber.

The body 1 is formed with a lateral extension 6 extending horizontallyfrom the lower portion of the body and the member 7 cxtending verticallyfrom the outer end portion of the member 6. The member 7 is joined atits upper end portion with the main portion of the body l. and is hollowthroughout its length to form a vertically disposed fuel well. Themember 6. is likewise, formed to provide a horizontally-disposed fuelpassage at its outer end in communication withthe lower end ofthevertical well formed by the member 7. The fuel passage formed by themember 6 extends. in= wardly a. distance into the lower end of the body1 and below the main airpassageand inlet 2.

A-jioat. chamber 3 is connected with and arrangedto supply fuel to thepassage formed in the member ,6. The'float chamber 3 is provided withthe hollow; lateral. extension i -which .is secured by means; of setscrews 01-3 similar fastening ,lmeans to the end -.of the carburetorbody 1 below the'fuel passage formed by the member 6. The lateralextension l is connected and in, communication with. thekfuel passageformed by the member 6,] by meansi-of a passageor duet formed in q theextension a and cOmmuni: eating with the fuel passage in the member 6,so.;-.a s ;to discharge fuel-ufrom thefloat chamber 3 into .thepassagein the. member 6. It wi'll;:be noted here=.that,;the,hollowextensions notonlyforms a conduit for passageoi tuelntrom the floatichamber to the fuelrpassa-ge in the, body 1 and member 6, butalsoprovides the means by which theifloat chamber 3 is attached to. andsupported from .the carburetor body 1.

Theouter cnd ot' the passagetformed in the member 6 adj acentrits. pointof discharge into the loweiwend of theyvertieal well 7 is closed by a.screw plug 5provided with a small longitudinal,ductt forming acontinuation of the passage. in the member 6 and providing a restrictedpassage 1 communicating with and discharging into the lower end of thewell? i11om the-iuel.passage in the member .6. Access tort-he plug 5 forremoval, replacement, or the like, vis;provided foiabya screw threadedopening in the wall of the member 7 opposite the plug 5 and nor, mallyclosed by aremovable screwthreaded plugoreap 8 Inthe particular type andarrangement illustrated in the accompanying drawings, a throttlemember.9, which comprises a cylinclrical portion or plug having adiametricalboreextending therethrough, is rotatably mounted in thebodyal, above and extending across -.the ,main air inlet'2, to controlthe "Z001? the.; passage therethrough.

.A lever 10 is mounted on andfixed to the throttle member. 9'by means ofwhichthe same is operated to control the passage rot air passing throughthe. bore of the member 9 from the air inlet and passage-2, in the body1.

the well T. The pipe-.11 extends long-L tion of the member tudinally andaxially a distance through the member 9, which is freely rotatablearound. the pipe 11, and terminates within the diametrical bore forked,through the plug 1)0l- 9 and adjacent the proximate. wall of the bore Inthis manner, the pipe 11 provides a connection between the vertical iuelwell? and the mixing chamber, through which air and fuel pass from thewell 7 to the mixingch-amber wheretit iis discharged and mixes with airpassing through the chamber. from the mainnir inlet and passage 2. Thethrottle 9 is rotatably moimted inthe bodyl by means of spindles or:shafts in suitable hearings or journal boxes formed in thebody 1. Thespindleeor shaft whiclrsupports the end oi the member-9 througlnwhich-the pipe 11' passesuis-rl'ormed by a hollow extcnsiontor sleeve 12mountedin ,a bee ring formed in the body 1 and the pipe 11 extends.longitudinally thro ughuthesleeve 12 into .the plug portions: of themember 9, as hcreinbclore described. p

A passage or duet l3 is formed in the body 1 and-extends, from a. pointin the bearing in which the sleeve 12 is mountedto the uppeiyend of thevertical fuel. well 7. The sleeve 12 is providediwith a preferably VwOl'triangular shapedopening 14. therethrough and'sopositioned therein astobe oppositethe open end-of thenduct 13 in the bearingof the sleeve 12formed in the body 1. The.foregoing arrangement of the opening 14 in thesleeve 12 and the end of duct 13 being sueh,-tha.t in certainpositionsof the-throttle 9,; the opening l l will register with theopenend. ofthe duct-l3 to permit air to pass therethrough and intothe fuel well 7.il heipositioniof opening 14. with respect'to thetendoi duct 13,determines the amount of air permitted; to pass therethrough into thewell. 7 and varies from completeregistration oiuopening 14 with the,cndot duct 1?}, through thc various positions throughwhichthe opening14. moves to apositionof non-registry with the duct 13 with the sleeve.12 substantially closing the-;ductagainstwntrancc and passage. of airtherethroughiinto the fuel well. 7. The position of the opening 14in thesleeve 12 is such that, when the.throttle is in open positionwith.the,borethereof in :full alincment and registry with the nrainairinlet 2, the opening .14 is not inwregisiry with the endof duct 13and-theslecve 12 substantially closesthe duct against passage of air tofuel welt? and when the member 1) in closedpositiomthat is the smallestworlo ing opening between inlet-2 and the mixing chamber,theopening 14;is in complete registry with duct 13 and airisisupplied to well 7 at themaxin'ium capacity of the duct 12-). The; amount of air supplied to well7 variesproportionally, between the two exllll treme positions abovereferred to, with the position of the throttle 9. Preferably, the end ofthe duct 13 which registers with the V-shaped or triangular opening 14in the sleeve 12, is of a similar V or triangular shape, so that whenthe throttle 9 is in open position the point or apex only of thetriangular openings may be in registry to permit a very small,comparatively negligible amount of air to enter the duct 13 and fuelwell 7. However, the invention is not limited to the particular shape ofthe opening 14 and the adjacent end of duct 13, as any suitable ordesired shape may be utilized.

A flanged sleeve 15 is mounted and conlined within the hollow shaftextension or sleeve 12 of the throttle 9 and is angularly adjustablewith respect thereto. A screw 16 extends through an elongated transverseslot cut in the sleeve 12 and confines the sleeve 15 in position withinthe sleeve 12. The screw 16 permits of angular adjustment of the sleeve15 and provides means for locking the same in the desired adjustedposition. The sleeve 15 is provided with an opening 17 through its walland the sleeve is so positioned within the sleeve 12 that the opening 17registers with the opening 14. The area of the opening 14 is vari ableby adjusting the position of the sleeve 15 and opening 17 with respectthereto so as to completely register therewith or partially cover thesame to decrease the size of the opening and the. amount of air whichpasses therethrough. From the foregoing, it is apparent that the sleeve12 is so aranged that with the throttle 9 in closed light load positionthe opening 14 therein is in full registry with the air duct 13 and thatwhen the throttle 9 is in open heavy load position, the opening 14 ispractically out of registry with the duct 13 to cause formation andsupply of a combustible mixture of maximum richness due to the need forsuch mixture at high speed of a motor, or heavy load as well understoodby those skilled in this art. Now, by the use of the. adjustable sleeve15 the size or area of the opening 14 can be varied to permit adjustmentof the carburetor to meet the requirements of a particular motor or forpeculiar working conditions.

A hollow extension 18 on the body 1 is in (.OlllllllllliCZll'lOll at itsinner end with the duct 13 and is provided with an opening in its outerend portion which communicates with the atmosphere and provides an airinlet opening for the admission of air to the hollow extension 18.

A. needle valve 19 is adjustably mounted in the extension 18 andcontrols the admission of air through the inlet in the extension 18 tothe duct 13. The valve 19 is adjusted when setting the carburetor andprovides a normally fixed air admission means but which may be varied onoccasions, independent of the adjustments of the sleeves 12 and 15, tothe duct 13 and fuel well 7. The valve 19 and extension 18 provide forthe variation of the fuel mixture for heavy load .working conditionswithout materially affecting whatever adjustments are made for lightload conditions by means of the adjustable sleeve 15 and opening 17. The

sleeve 15 with the throttle in open position for heavy load operation ofthe motor is in a position substantially closing the duct 13 againstadmission of air to vary the mixture in the fuel well 7, therefore, in

order to make any desired adjustment for heavy load conditions the valve19 is operated to admit air to the well 7, and it is clear that thisadjustment will have but small effect upon the adjustment made by thesleeve 15 for light load conditions with the duct 18 open to admit theentry of comparatively large quantities of air to the well 7.

An air passage 20 is formed in the body 1 and is provided with an airinlet 21 open to atmosphere through a side of the body. A slidable plate23 having an opening adapted to be 1110X'8Cl to and from registrz tionwith the inlet 21 to vary the amount of air admitted thereto or tocompletely shut off the same, is adjustably mounted on the body 1 overthe opening or inlet 21. The throttle 9 is provided with a duct 22 whichconnects the air passage 20 with the mixing chamber, so that, with theinlet 21 open air passes from atmosphere to the passage 20 and throughduct 22 into the mixing chamber where it is mixed with the air and fuelpassing therethrough.

,The air passage 20 provides an additional means for admitting air intothe mixing chamber other than by the main air inlet 2. hen the throttleis in open heavy load position, opening of the passage 20 will havepractically no effect on the 1nixture formed as the quantity of airadmitted thereby is comparatively small compared to the quantityadmitted through inlet 2, but when the throttle 9 is in partially closedlight load position the quantity of air admitted to the mixing chamberis materially reduced so that opening of passage 20 will haveconsiderable effect in vary ing the mixture formed. Hence, air passage20 provides an additional adjustment increasing the range through whichthe mixture at light load positions of the throttle can be varied.

A hollow projecting member 24 is arranged on the body 1 in communicationwith the fuel well 7. Any suitable vacuum gauge may be mounted in andconnected with the hollow member 24 to indicate the degree of vacuumexisting in the fuel well 7, and hence by suitable calibv'ation, as willHit) - fuel; therethrough fromthrottle. 9 is be; readily; understood bythose skilled in the art, the vacuum; in; the well can be readilydetermined It will be: understood, oft course, that the: hollow member24 is nor-i'nally, closed, either by a. vacuum gauge orpin any of anumberof: well knownways. The, operation; of: a: carburetor: embodyingthe variousfeatures of, my. invention as hereinbefore referred :,to and.described will now be explained; The arrangement and mounting of: the.screw plug 5v provided witlntlieduct/51 therethrough forms aconstrictionin:the. passageformed .by the memher 6: and offers.resistance. tothezfl'ow of the:fioat chamber 3zto :the fueliwell 7. ithe-motor. towhich the: carburetor; is connected at: rest, fuel flows-sfrom' thefloatch-amberzfito the verti+ cal fuel Wel-bZto :a level thereincorrespond ingr-togthe level inzthe floati will, be readily!understood,v which level is above the lowercendzof thepipe 11.: WVhen amotor is started, therefore, solid fuel'is drawn by suction created by;the motor from the fuel: well 7 and. discharged into the motor untiltheelevelof: fuel in the. well is lowered belowtheaend of the pipe- 11,after. which. airis drawn into the well- :and mixedwiththe fuel suckedvtherefromzias will be explained:hereinafter. During the operation. of.the motor fuel continues to flow from: the float chamber 3 through thepassagei'ormed by themember 6 andthe duct- 5*forming a constrictiontherein and intothe fuellwell. 7.7 Fueliis drawn by suctionzcreated bytheamotor from the fuel well 27 throughsthe pipezllnnixing with the airtherein the emulsion thus. formed being discharged into the diametricalbore of the throttle member '9 where .it is mixed with airpa-ssingx:therethrough from; the main airinletr2"to*-fornr a combustiblemixture which is drawn: into the motor and theregzignited in a manner.wellisknown and understoodby those-rskilled'ini. this art.

Assume that a motor with which the carburetor'is operatively connectedis working lightly loaded, and at low speed, then the in; partiallyclosed position with a maximum choke; effect,- that is, the "passagethrough the throttle -9 is materially reduced in area which.reducesthequantity of air drawn; into the i passage in the throttle 9fronrtheimaint air inlet-2. Now, with the throttle :ginuthe; above 1position the 1 opening 14; 2111 .the :sleeve 121's inuregistry 1 withthe duct :13 to, 'r'pern'iit approximately 3 maximum flow of air to theduct 13 and =well:-7,' as hereinbeforew described and explained. Thus;vitwis-iseen that with :the throttle 9 in light loadpposition and theresulting-reduced quantity ofv air: passing: into the throttleipassageithat the quantity of fuel drawn: from: the -'welli 7 for A mixingtherewith in: the throttlek passage aiss-propor chamber, as

tionately reduced to form the proper combustible: mixture for operatingthe motor, by thequantity ofairadmitted to the fuel wellithroughopeningi134 and duct 13. As thethrottle 9 is opened to increase the speedandpower of the-motor and increase the quantity of air drawn from the mainain' inlet 2, the sleeve 12 is rotated and correspondingly reduces thearea of the opening 14 in registry with the duct 13', so that: thequantity of air admitted to the \V8ll 7! from atmosphere is reduced andthe quantity of fuel drawn from the well 7 through: pipe 11 anddischarged into the passage. through throttle 9 is correspondinglyincreased: to form a proper combHStlblGJIllXtHl'Q with the air from themain airi inlet 2. lVhen the carburetor of the invention-is operatingwith amotor working atimaximum speed or heavy load the throttle 9.isinopen'positionwith the passage therethrough in registry with themain air inlet 2,"so that a maximum quantity of air passes therethrough.In this position of thewthrottle the sleeve 12 is rotated topositi'oniwith the port or opening 14 substantiallyrout of registry withthe duct 13, so that the'well 7 is practically cut off fromcommunication with the atmosphere and substantially noair is drawn intowell 7. Thiskresults in maximum quantity of fuel being drawn into thepassage through tl1rottle=.9 for mixing with the increased quantity ofair admitted from air inlet 2 to form a proper and eflicient combustiblemixture for operating the motor at maximum speed or heavy load. It willbe apparent from the foregoing that the operation of the carburetorbetween the two extremes of maximum light load and maximum heavy loadprovides for varyingtheproportions of fuel and air forming thecombustible mixture coresponding to the requirements of the motor at thespeed or load at which it is operated.

The rotatable sleeve 15 provided with the portor opening 17 forms themeans for adjusting the carburetor for light load or low speedoperatingconditions. 15y rotatingthe sleeve 15 the area ofthc port or opening ldin the sleeve 12 can be varied to regulate the quantity of air admittedto the well Ttlnough duct 13 from atmosphere and when the properadjustment has been-made the sleeve 15 is set at that point by meansofthe set'screw 16.

The combustible mixture at heavy loads may be regulated bymeans of theneedle valve 19 to increase-or reduce the air admittedwintothefuel well7 through member 18 and duct 13.- It is clearly seen that any adjustmentof needle valve 19 will have-no material effect on or disturb theadjustment=of the carburetor for light load operations, as at lightloads the duct l3 is in partial or substantially complete registrationwith the opening 14: in sleeve 12 and therefore, the relatively smalladded admission of air by needle valve 19 will have no material effect.After the proper adjustment of needle valve 19 is made for heavy loadoperation the valve is set.

The amount of air passing from the main air inlet 2 to the passage inthrottle 9 can be increased or augmented by opening the plate 28 toadmit air to the passage 20, duct 22 and discharged from duct 22 intothe passage in the throttle 9. This adjustment, as pointed outhereinbefore, is made to admit air when the throttle is partially closedand the main air inlet is correspondingly reduced, so that a furtheradjustment of the mixture may be made at light loads When it is foundthat the air admitted from the main air inlet is insufficient, and theadjustment of sleeve 15 to maximum open position has not produced thedesired results.

It is evident that various changes, modifications and variations mightbe resorted to Without departing from the spirit and scope of myinvention and hence I do not wish to limit myself to the exactdisclosures hereof.

Desiring to protect my invention in the broadest manner legally possibleWhat I claim is:

1. In a carburetor, a mixing chamber, a throttle controlling thedischarge of combustible mixture from said mixing cham her, a fuel Well,a fuel supply pipe from said Well to and discharging into said mixingchamber, means for admitting air to said fuel Well to form a primarymixture therein for discharge through said fuel supply pipe into saidmixing chamber, the said air admitting means consisting of an inlet fromatmosphere for discharging air into said fuel Well, a valve controllingsaid inlet and operated by the said throttle, and means for adjustingthe area of said fuel Well inlet independently of the operation of saidvalve by the said throttle.

2. In a carburetor, a mixing chamber, a throttle controlling thedischarge of co1nbustible mixture from said mixing chamber, a fuel well,a fuel supply pipe from said Well to and discharging into said mixingchamber, and means for admitting air to said fuel Well to form a primarymixture therein for discharge into said mixing chamber, the said airadmission means consisting of a passage open to atmosphere andcommunicating With said fuel Well, a valve operated by said throttle fordecreasing the area of said fuel Well air passage as the throttle isopened and for increasing the area thereof as the throttle is closed,adjusting means for varying the maximum area of said passageindependently of said throttle operated valve, and auxiliary means foradmitting air to said fuel well independently of said throttle operatedair admission means.

3. In a carburetor, a mixing chamber, a throttle controlling dischargeof combustible mixture from said chamber, a fuel Well, a float chamberhaving a connection With and discharging into said fuel well, arestricted passage in said connection, a fuel supply pipe from said fuelWell to said mixing chamber, means for admitting air to said fuel Wellbetween the restricted passage in the connection from said float chamherand the fuel supply pipe, a rotary valve controlling said air admissionmeans and operated by said throttle, and a sleeve valve cooperating Withsaid rotary valve and operable independently of said rotary valve forvarying the quantity of air admitted by said rotary valve.

Dated this 5th day of December, 1919.

CHARLES WILLIAM GODSON LITTLE.

